Erroneous HbA1c measurements in the presence of β-thalassemia and common Chinese hemoglobin variants.

Background: HbA1c is a widely used biomarker for the management of diabetes mellitus and can be quantified from blood samples by using various methods, including ion-exchange high-performance liquid chromatography (HPLC), boronate affinity HPLC, and capillary electrophoresis (CE). Here, we evaluated the accuracy of four separation methods for determination of HbA1c values in Chinese patients with different hemoglobin disorders.

Methods: Blood samples from normal patients, patients with β-thalassemia, patients exhibiting heterozygosity, and patients exhibiting homozygosity were analyzed using ion-exchange HPLC (Variant II Turbo, Bio-Rad and Adams A1c HA-8160, Arkray, run in diabetes mode), boronate affinity HPLC (Ultra2, Trinity Biotech), and CE (Capillarys 2 Flex Piercing, Sebia).

Results: Samples from patients with β-thalassemia produced significant positive biases on the Variant II Turbo system compared to the other three systems. For heterozygous βA/βE patients, a good agreement was observed between Capillarys 2 Flex Piercing and Ultra2 systems, while a significant negative bias was observed between HA-8160 and Capillarys 2 Flex Piercing systems and between Variant II Turbo and Capillarys 2 Flex Piercing systems. For homozygous (βE/βE) patients, a clear context without HbA, all systems except the Capillarys 2 Flex Piercing system yielded random HbA1c results. Only the Capillarys 2 Flex Piercing system could detect all hemoglobin variants tested.

Conclusions: β-Thalassemia can cause errors in HbA1c determination using the Variant II Turbo system. HbE heterozygosity or HbE homozygosity also complicated HbA1c measurements. The Capillarys 2 Flex Piercing system detected all Hb variants and HbA1c in patients with β-thalassemia and could provide measurements with high accuracy.